A well-known engine for a working machine includes a crankshaft on which a cooling fan is coaxially mounted. A staring pulley is coaxially mounted on the cooling fan. The pulley is engageable with a recoil starter. The pulley is hollow and the cooling fan is formed integrally with an outer circumference of the pulley.
To start the engine, a cable of the recoil starter is manually pulled by an operator to rotate the pulley (i.e., the cooling fan). The rotation of the cooling fan rotates the crankshaft to thereby start the engine. Upon the starting of the engine, the crankshaft rotates the cooling fan, such that the cooling fan cools a cylinder block of the engine by delivering a cooling air thereto. Such an engine is disclosed in, for example, in JP-B-4223919.
For the engine of patent literature 1, the cooling fan is mounted on the crankshaft. The starting pulley is coaxially disposed in the middle of the cooling fan such that the starting pulley is disposed on the crankcase. Due to this arrangement, it is difficult for the cooling fan to deliver a cooling air to the crankcase; hence, some measures should be taken to cool an engine oil in the crankcase. In addition, the starting pulley, which is hollow, is required to have an increased thickness for a sufficient rigidity, particularly, at its portion engaging the recoil starter.
Some engine for a working machine includes a crankshaft on which a motor is coaxially disposed. A centrifugal fan is coaxially disposed on an output shaft of the motor. An axial fan is coaxially disposed inside the centrifugal fan. On the opposite side of the centrifugal fan and the axial fan is disposed a starting pulley engageable with the pulley.
For an engine disclosed in JP-A-2014-151415, an axial fan is disposed inside a centrifugal fan to deliver a cooling air to a motor and a cylinder block of the engine, such that the cooling air delivered by the axial fan cools an engine oil in a crankcase of the engine.
For the engine of JP-A-2014-151415, a starting pulley, which is disposed opposite the centrifugal fan and the axial fan, is a separate member from these fans. That is, the starting pulley is independently provided in addition to the centrifugal fan and the axial fan. The provision of such an additional member separate from the fans is an obstacle to reducing the number of the members. The starting pulley is hollow, as in the engine of JP-B-4223919, and hence the pulley is required to have an increased thickness for a sufficient rigidity, particularly, at its portion engaging a recoil starter.